1. Field of the Invention
The present invention relates to AFM (Atomic Force Microscope) tweezers with a probe that can be used as a probe tip for use in a scanning probe microscope, to a method for producing such AFM tweezers, and to a scanning probe microscope.
2. Description of Related Art
So-called AFM tweezers that include two probes between which a sample is to be inserted and grip/release the sample have been developed to be applied to manipulation of samples to be observed by a scanning probe microscope.
Such AFM tweezers in a cantilever used in, for example, a scanning probe microscope include the following: (1) AFM tweezers including two carbon nanotubes attached to a probe tip attached to the tip of a cantilever made of silicon (see Japanese Laid-Open Patent Publication No. 2001-252900); (2) AFM tweezers including carbon nanotubes attached to a glass tube that serves as a cantilever; and (3) AFM tweezers including two cantilevers fabricated on a silicon substrate by a MEMS (Micro Electro Mechanical Systems) process.
In the tweezers (1) and (2) above, electrostatic electricity is applied between carbon nanotube probe tips to open/close the two carbon nanotubes. Examples of the tweezers (3) above include the following. In one example, current is applied to bases of the cantilevers of the tweezers to generate heat and linear expansion of silicon cantilevers due to the generated heat is amplified to drive the cantilevers. In another example, a comb-shaped electrostatic actuator is provided to enable the two cantilevers to grip an object therebetween (see Tetsuya Takekawa, Gen Hashiguchi, Eiichi Tamiya, et al., “Study of AFM tweezers for manipulation of nano objects”, Extended Summary of The Institute of Electrical Engineers of Japan, Trans. SM, Vol. 125, No. 11, 2005).
Conventional devices, however, are each configured to grip a sample with very thin carbon nanotubes, so that they grip the samples only unstably and manipulations for gripping are difficult to do. The AFM tweezers described in “Study of AFM tweezers for manipulation of nano objects” include a knife-edged probe, and the shape of the probe tip is reflected on the obtained AFM image to produce a false image. As a result, shape information such as width and height of the sample gripped by the tweezers is difficult to obtain.